Oxidation- and low temperature-resistant glycerides of natural fatty acids

ABSTRACT

GLYCERIDE MIXTURES RESISTANT TO OXIDATION AND LOW TEMPERATURES COMPRISING 10-99% BY WEIGHT OF DIACETYL MONOMONOHEXADECANOLY TRIGLCERIDE, AND/OR UP TO 90% BY MONOHEXADECANOYL TRIGLYCERIDE, AND/OR UP TO 90% BY WEIGHT OF DIACETYL MONOTETRADECANOYL TRIGLCERIDE, AS WELL AS OPTIONALLY UP TO 10% BY WEIGHT OF AN ACETYL DIALKANOYL TRIGLYCERIDE WHEREIN THE ALKANOYL GROUPS THEREOF HAVE 1216 CARBON ATOMS.

United States Patent 3,748,265 OXIDATION- AND LOW TEMPERATURE-RESIST-ANT GLYCERIDES OF NATURAL FATTY AClDS Heinrich Biinger, Witten-Bommern,and Gustav Renclrhofi, Witten, Germany, assiguors to Dynamit NobelAktiengesellschaft, Troisdorf, Germany N0 Drawing. Filed Mar. 1, 1971,Ser. No. 119,828

lint. Cl. C091; 3/20 US. Cl. 252-]. 13 Claims ABSTRACT OF THE DISCLOSUREGlyceride mixtures resistant to oxidation and low temperaturescomprising -99% by weight of diacetyl monododecanoyl triglyceride, up to25% by weight of diacetyl monohexadecanoyl triglyceride, and/or up to90% by Weight of diacetyl monotetradecanoyl triglyceride, as well asoptionally up to 10% by weight of an acetyl dialkanoyl triglyceridewherein the alkanoyl groups thereof have 12- 16 carbon atoms.

Liquid glycerides of natural fatty acids are employed in a great varietyof fields, for example in the pharmaceutical and cosmetic industries, in[food technology, as well as in the technical sector. In most cases,they must meet the requirements of being physiologically accetpable aswell as nonfreezing, capable of readily dissolving fats and waxes, andhaving a low vapor pressure.

Glycerides are employed, for example, which contain bound therein alsounsaturated fatty acids, in addition to saturated ones. Such glyceridesare prone to autoxidation; they become more or less readily rancid independence on the external conditions (Neuwald, F.; Winkler, A.: J. Soc.Cosmetic Chemists 16 (1965), pp. 679-85). This phenomenon can beprevented by antioxidants; however, the addition of such agents is inmany cases undesirable.

Furthermore, triglycerides of fully saturated fatty acids are knownwhich are liquid at low temperatures (for example, German Pat. 944,394).However, the glycerides contain considerable proportions of [fatty acidresidues of less than 12 carbon atoms. By minor splitting reactionstaking place during use, for example by lipases, a typically soapy odordevelops.

Also, liquid glycerides containing aceto groups have been described inthe literature (The Journal of the American Oil Chemists Society 35(1958), pp. 122-7). However, these glycerides, due to their composition,like wise exhibit the tendency toward rancidity or toward splitting offfatty acids causing an intensely soapy odor.

It has now been found that a triglyceride fulfills all practicalrequirements and does not exhibit the disadvantages of the triglyceridesknown heretofore, i.e. a triglyceride which is oxidation-resistant, doesnot liberate intensely soapy smelling fatty acids upon a splittingreaction, does not exhibit any crystalline deposits after being storedfor a longer period of time at 0 C., and is not hydrolyzed upon contactwith Water, if the molecule of such triglyceride exhibits two acetylgroups and one dodecanoyl group.

All of these properties are also retained if this triglyceride ispresent in a mixture with glycerides of a specific structure modifiedwith respect to the higher fatty acid residue. The mixture component canbe a triglyceride containing, in addition to two acetyl groups, theresidue of a fatty acid exhibiting more than 12 carbon atoms. Also inthis case, the formation of fatty acids of an intensely soapy odor isavoided during the occurrence of a splitting reaction. In view of therequirement that a liquid 3,?43,Z05 Patented July 24, 1973 "iceconsistency must be present at 0 C., there is, in this case, merely alimitation with respect to the chain length of the acid residue, whichlatter is to have no more than 16 carbon atoms. Such mixtures cancontain, in addition to diacetyl monododecanoyl glycerol, up to 25% byweight of diacetyl monohexadecanoyl glycerol or up to by weight ofdiacetyl monotetradecanoyl glycerol.

It is also possible to admix to the triglyceride with two acetyl groupsand one dodecanoyl group in the molecule, as well as to theabove-mentioned mixtures, up to 10% by weight of acetyl dialkanoylglycerol, wherein the alkanoyl groups, in turn, can contain l2-16 carbonatoms.

Furthermore, such a number of diglycerides can be contained therein thata hydroxyl number of up to 20 results.

The glyceride of this invention can be produced, according to oneprocess, by the esterification of lauric acid with excess glycerol andisolation of the thus-formed mono-glyceride by molecular distillation,whereupon an acetylation of the monoglyceride is connected with aceticanhydride to produce the triglyceride. Furthermore, the triglyceride ofthis invention can be obtained by the interesterifieation oftridodecanoyl glycerol with triacetin and separation of the reactionproduct by molecular distillation.

Since the glyceride of this invention can also retain its advantageousproperties in a mixture with other glycerides, it is possible to make asuitable selection, during the manufacture thereof, among the technicalfatty acid blends commercially available.

EXAMPLE 1 Lauric acid monoglyceride was enriched by moleculardistillation from a lauric acid partial glyceride mixture Thismonoglyceride was pure, as determined by gas chromatography, andexhibited the following characteristics:

Melting point C 63.0 Acid number 0.88 Saponification number 207 Hydroxylnumber 409 Fifty grams of this monoglyceride was refluxed with g. ofacetic anhydride under normal pressure for two hours. Then the aceticacid and excess acetic anhydride were distilled off, at last undervacuum. Thereafter, steam was passed through the product for two hoursat C. and 20 torr (mm. Hg). The product, after this step, exhibited ahydroxyl number of 0, an acid number of 0.8, and a saponification numberof 467 (calculated value: 469). The refractive index at 20 C., measuredby dylight, was 1.4475; the substance solidified at 2l.0 C. and boiledat 197 C. and 1.5 torr.

EXAMPLE 2 A lauric acid partial glyceride fraction obtained duringmolecular distillation with the following data: melting point, 60 C.;hydroxyl number, 381; saponification number, 214; acid number, 2.2;consisted, in accordance with analysis by gas chromatography, of 90.5%monoglyceride and 9.5% diglyceride. This fraction was acetylated incorrespondence with Example 1, thus resulting in a product having ahydroxyl number of 0, a saponification number of 462, and an acid numberof 2.35. This product remained completely clear after being stored forone week at 0 C.

EXAMPLE 3 Analogously to Example 1, 100 g. of myristic acidmonoglyceride (diglyceride content: 8.8% by weight;

melting point: 69 0.; hydroxyl number: 330.0; saponification number:117.5; acid number: 1.28) was reacted with 100 g. of acetic anhydrideand then worked up. A mixture of 85 parts by Weight of the product(hydroxyl number: saponification number: 469; acid number: 0) with 15parts by weight of diacetyl monododecanoyl glycerol remained completelyclear after a longer period of storage at 0 C.

EXAMPLE 4 78 parts by weight of diacetyl monododecanoyl glycerol wasmixed with 22 parts by weight of diacetyl monohexadecanoyl glycerol. Themixture remained completely clear after a longer period of storage at 0C.

EXAMPLE 5 Ten parts by weight of diacetyl monohexadecanoyl glycerol, 40parts by Weight of diacetyl monotetradecanoyl glycerol, and 50 parts byweight of diacetyl monododecanoyl glycerol were mixed with one another.The mixture remained completely clear after being stored at 0 C. for alonger period of time.

We claim:

1. An oxidation-resistant glyceride mixture, which does not exhibitcrystalline deposits at 0 C., does not liberate fatty acids having anintensely soapy odor when cleaved and does not hydrolyze with water,consisting essentially of to 99% by weight of diacetyl monododecanoyltriglyceride, up to 90% by weight of diacetyl monotetradecanoyltriglyceride, and up to 25% by weight of diacetyl monohexadecanoyltriglyceride.

2. An oxidation-resistant glyceride mixture, which does not exhibitcrystalline deposits at 0 C., does not liberate fatty acids having anintensely soapy odor when cleaved and does not hydrolyze with Water,consisting essentially of 10 to 99% by weight of diacetyl monododecanoyltriglyceride and up to 90% by weight of diacetyl monotetradecanoyltriglyceride.

3. An oxidation-resistant glyceride mixture, which does not exhibitcrystalline deposits at 0 C., does not liberate fatty acids having anintensely soapy odor when cleaved and does not hydrolyze with water,consisting essentially of 75 to 99% by weight of diacetyl monododecanoyltriglyceride and 1 to 25% by weight of diacetyl monohexadecanoyltriglyceride.

4. An oxidation-resistant glyceride mixture, which does not exhibitcrystalline deposits at 0 C., does not liberate fatty acids having anintensely soapy odor when cleaved and does not hydrolyze with water,consisting essentially of 10 to 99% by weight of diacetyl monododecanoyltriglyceride, up to 25% by weight of diacetyl monohexadecanoyltriglyceride, and up to 10% by weight of an acetyl dialkanoyltriglyceride, the alkanoyl groups thereof having from 12 to 16 carbonatoms.

5. An oxidation-resistant glyceride mixture, which does not exhibitcrystalline deposits at 0 C., does not liberate fatty acids having anintensely soapy odor when cleaved and does not hydrolyze with water,consisting essentially of 10 to 99% by weight of diacetyl monododecanoyltriglyceride, up to 25% by weight of diacetyl monohexadecanoyltriglyceride, up to 10% by weight of an acetyl dialkanoyl triglyceride,the alkanoyl groups thereof having from 12 to 16 carbon atoms, and up to90% by weight of diacetyl monotetradecanoyl triglyceride.

6. An oxidation-resistant glyceride mixture, which does not exhibitcrystalline deposits of 0 C., does not liberate fatty acids having anintensely soapy odor when cleaved and does not hydrolyze'with water,consisting essentially of 10 to 99% by weight of diacetyl monododecanoyltriglyceride, up to 90% by weight of diacetyl monotetradecanoyltriglyceride, and up to 10% by weight of an acetyl dialkanoyltriglyceride, the alkanoyl groups thereof having from 12 to 16 carbonatoms.

7. An oxidation-resistant glyceride mixture, which does not exhibitcrystalline deposits at 0 C., does not liberate fatty acids having anintensely soapy odor when cleaved and does not hydrolyze with water,consisting essentially of 10 to 99% by weight of diacetyl monododecanoyltriglyceride, up to by weight of diacetyl monotetradecanoyltriglyceride, up to 25% by weight of diacetyl monohexadecanoyltriglyceride, and suflicient diglycerides that the resultant glyceridemixture has a hydroxyl number of up to 20.

8. An oxidation-resistant glyceride mixture, which does not exhibitcrystalline deposits at 0 C., does not liberate fatty acids having anintensely soapy odor when cleaved and does not hydrolyze with waterconsisting essentially of 10 to 99% by weight of diacetyl monododecanoyltri-= glyceride, up to 90% by weight of diacetyl monotetradecanoyltriglyceride, and sufiicient diglycerides that the resultant glyceridemixture has a hydroxyl number of up to 20.

9. An oxidation-resistant glyceride mixture, which does not exhibitcrystalline deposits at 0 C., does not liberate fatty acids having anintensely soapy odor when cleaved and does not hydrolyze with water,consisting essentially of 75 to 99% by weight of diacetyl monododecanoyltriglyceride, 1 to 25% by weight of diacetyl monohexadecanoyltriglyceride, and sufiicient diglycerides that the resultant glyceridemixture has a hydroxyl number of up to 20.

10. An oxidation-resistant glyceride mixture, which does not exhibitcrystalline deposits at 0 C., does not liberate fatty acids having anintensely soapy odor when cleaved and does not hydrolyze with water,consisting essentially of 10 to 99% by weight of diacetyl monododecanoyltriglyceride, up to 25% by weight of diacetyl monohexadecanoyltriglyceride, up to 10% by weight of an acetyl dialkanoyl triglyceride,the alkanoyl groups thereof having from 12 to 16 carbon atoms, andsufficient diglycerides that the resultant glyceride mixture has a'hydroxyl number of up to 20.

11. An oxidation-resistant glyceride mixture, which does not exhibitcrystalline deposits at 0 C., does not liberate fatty acids having anintensely soapy odor when cleaved and does not hydrolyze with water,consisting essentially of 10 to 99% by weight of diacetyl monododecanoyltriglyceride, up to 25 by weight of diacetyl monohexadecanoyltriglyceride, up to 10% by weight of an acetyl dialkanoyl triglyceride,the alkanoyl groups thereof having from 12 to 16 carbon atoms, up to 90%by weight of diacetyl tetradecanoyl triglyceride, and sufficientdiglycerides that the resultant glyceride mixture has a hydroxyl numberof up to 20.

12. An oxidation-resistant glyceride mixture, which does not exhibitcrystalline deposits of 0 C., does not liberate fatty acids having anintensely soapy odor when cleaved and does not hydrolyze with water,consisting essentially of 10 to 99% by weight of diacetyl monododecanoyltriglyceride, up to 90% by weight of diacetyl monotetradecanoyltriglyceride, up to 10% by weight of an acetyl dialkanoyl triglyceride,the alkanoyl groups thereof having from 12 to 16 carbon atoms, andsufiicient diglycerides that the resultant glyceride mixture has ahydroxyl number of up to 20.

13. An oxidation-resistant glyceride mixture, which does not exhibitcrystalline deposits at 0 C., does not liberate fatty acids having anintensely soapy odor when cleaved and does not hydrolyze with water,consisting essentially of: (a) 10 to 90% by weight of diacetylmonododecanoyl triglyceride and another triglyceride component selectedfrom the group consisting of (b) up to 25% by weight of diacetylmonohexadecanoyl triglyceride, (c) up to 10% by weight of acetyldialkanoyl triglyceride, the alkanoyl groups thereof having from 12 to16 carbon atoms, (d) up to 90% by weight of diacetyl monotetradecanoyltriglyceride and a combination of (b), (c), and (d); and (e) sufficientdiglycerides that the resultant glyc- 3,748,265 5 6 eride mixture has ahydroxyl number of up to 20, each OTHER REFERENCES weight percent beingbased on the total weight of the I. Am Oil Chemists, Soc March 1958 VOLXXXV glyceride mixtufe- No. 3, p. 122-127, Present Status ofAcetoglycerides.

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